1. Technical Field
The present invention relates to a multilayer ceramic device, and more particularly, to a multilayer ceramic device capable of preventing deterioration of a function thereof due to generation of a crack.
2. Description of the Related Art
A chip component such as a general thin film type multilayer ceramic capacitor (MLCC) is configured to include a device body, internal electrodes, external electrodes, and the like. The device body has a structure in which a plurality of dielectric sheets called green sheets are multilayered, and the internal electrodes are provided to the dielectric sheets, respectively. In addition, the external electrodes have a structure in which they cover both end portions of an outer portion of the device body while being electrically connected to the internal electrodes.
Generally, since the multilayer ceramic device is designed to be focused on improving characteristics thereof, it is relatively vulnerable to external physical pressure or impact, thermal impact, other vibrations, or the like. Therefore, when the physical or thermal impact is applied to the multilayer ceramic device, a crack is generated in the device body. The crack is mainly generated in a surface of the device body adjacent to a distal end portion of the external electrode and then progresses to an inner portion of the device body. When the crack progresses to an active region of the device body, the multilayer ceramic device has a difficulty in performing its function.
In order to prevent damage to the chip component due to the crack, a technology of allowing the external electrode to have a structure capable of absorbing external impact has been suggested. To this end, the external electrode may have a structure in which it includes an internal metal layer directly covering the device body, an external metal layer exposed to the outside, and an intermediate layer interposed between the internal metal layer and the external metal layer. However, since the intermediate layer is made of a mixture material of a metal and a polymer resin, the polymer resin is thermally decomposed in a reflow or wave soldering process for mounting the chip component, such that the internal metal layer and the intermediate layer are separated from each other, thereby generating an internal void. The void and delamination phenomenon as described above, which is a problem of the chip component itself rather than a problem due to driving of an electronic apparatus in which the chip component is mounted, deteriorates a function of the chip component.
As another method, there is a method of providing a reinforcing pattern in the device body adjacent to a point at which the crack is frequently generated to block progress of the crack. However, since the number of multilayered patterns should be increased in the device body in order to apply the reinforcing pattern as described above, a cost required for manufacturing the device is increased and a thickness of a dielectric is relatively decreased, such that it is difficult to implement a high capacitance.